He has been on the fringes of the first team squad for the last month, featuring against Wolves in the previous round of the League Cup, but forcing his way into the starting line-up has not happened yet.
And with Eden Hazard, Oscar, and Juan Mata in inspired form in front of him, its no slight on Marin that he hasn't established himself just yet.
This is why we are tipping him to do just that tomorrow night, when Chelsea host Manchester United in a re-match of the weekend's fixture, this time in the Capital One Cup.
Marin was on the bench at the weekend, and Roberto di Matteo is likely to rotate his squad to give players like Moses, Sturridge, and Marin a chance.
The talented German should thrive on the big match atmosphere, and it is the perfect opportunity for him to make a statement. If he can steal the show as he will wish to, the level of opposition means he will make himself very difficult to leave out of the first team in the Premier League.
That is the challenge, and carrot being dangled in front of him, and with United's potentially weakened defence will have to be on their game.
While Marin seems destined to start for Chelsea, whether or not to include Lucas Piazon from the start is another dilemma for Roberto di Matteo.
Piazon is Chelsea's top teenage talent, scoring against PSG in pre-season, and featuring against Wolves last round. He didn't score in the 6-0 win, but played a big role in the win, and is hoping for another big chance tomorrow night.
The Brazilian put United to the sword in the FA Youth Cup last season, and will relish the task of doing the same for the senior side. The question is whether Chelsea will give him the nod from the start or the bench.
A frontline of Sturridge, supported by Moses-Piazon-Marin is a mouth watering one, and not a bad 'B' line-up to support their first choice Torres-Oscar-Mata-Hazard quartet. We hope from a neutral perspective that Di Matteo trusts his supporting cast to do the damage tomorrow night.
Is this going to be Marin's big night? Should Piazon start? What do you think?
image: © 2e14